An organic silicone resin has been conventionally used as a coating agent for giving water repellency to skin or hair to protect their surfaces. Examples of the organic silicone resin include a resin (hereinafter, referred to as a silicone resin) composed of M unit expressed by general formula RX3SiO1/2 (where RX represents a hydrogen atom or an organic group), Q unit expressed by SiO2, D unit expressed by RX2SiO, and T unit expressed by RXSiO3/2; and a resin (hereinafter, referred to as a silicone-modified acrylic polymer) mainly composed of a copolymer of a silicone macromonomer having a (meth)acrylic group with other polymerizable monomer.
A cosmetic containing the organic silicone resin with the silicone resin structure is characterized by inhibiting secondary adhesion and giving water repellency. However, the silicone resin is a rigid resin having low flexibility and is difficult to form a transparent and flexible film. Thus, this resin has difficulties in feeling of use as well as adhesiveness to the skin or hair in that the cosmetic containing this resin gives tension feeling and easily causes cracks and separation of the film formed by the cosmetic. To remedy the difficulties, compositions containing a highly polymerized polysiloxane in addition to the silicone resin have been proposed (Patent Documents 1 to 3, for example). These compositions can significantly improve adhesiveness of the resulting film, but still have problems of stickiness and secondary adhesion due to the highly polymerized polysiloxane.
In addition, a composition containing a specific silicone resin and a specific polysiloxane and oil material with a specific ratio has been proposed (Patent Document 4, for example). This composition can form a film having significantly improved adhesiveness and stickiness, but is inadequate to meet recent requirements of users.
On the other hand, the silicone-modified acrylic polymer enables formation of a film having water repellency, flexibility, and high adhesiveness and makes a cosmetic containing this polymer smooth and glossy. In particular, the silicone-modified acrylic polymer has been developed to have miscibility with various oil materials (Patent Documents 5 to 8). However, a film formed by such a silicone-modified acrylic polymer has low strength and easily causes cosmetic deterioration. Thus, this polymer is still inadequate to meet the recent requirements of users.
To make the best use of the silicone resin and the silicone-modified acrylic polymer, a mixture thereof is proposed as a film-forming agent to form a film having non-stickiness, adhesiveness, and excellent abrasion resistance. However, since the silicone resin is not miscible with the silicone-modified acrylic polymer, this mixture is inadequate to form a transparent film.